Dave
I'm glad I emphasised the "Unless I'm wrong" part of my post.
Regards
Michael

"Dave Thomas" wrote:

This formula checks for data in cell A1 on both sheet1 and sheet2 or no data
in either
cell and generates an error if so. If only one of the two cells has data, it
copies the data to sheet3.

The formula entered on some cell on Sheet3 is:

=IF(OR(AND(Sheet1!A1="",Sheet2!A1=""),AND(Sheet1!A 1<"",Sheet2!A1<"")),"Houston,
we have a problem",IF(Sheet1!A1<"",Sheet1!A1,Sheet2!A1))

"Fritz" wrote in message
...
I have 3 worksheets in one workbook.
Either sheet 1, or sheet 2 will have data in it but not both.
The third worksheet is a summary report that I want to draw certain cell
contents into ie. Unit #, Serial Number, Make, Model etc.

Sounds like an "either/or" function. Or should I use an "If then"
function?